In LTE (Long Term Evolution) is studied a base station system for separating and installing a radio control apparatus (for example, BBU: BaseBand Unit) for performing baseband processing and the like, and a radio apparatus (for example, RAU: Radio Antenna Unit) for transmitting and receiving radio signals with an antenna (for example, Non-patent Document 1).
In this base station system, the radio control apparatus (BBU) and radio apparatus (RAU) are connected with an optical transmission path (optical cable). More specifically, a signal from the radio control apparatus (BBU) is optically transmitted to the radio apparatus (RAU) via an interface such as a CPRI (Common Public Radio Interface). The radio apparatus (RAU) converts the signal from the radio control apparatus (BBU) into a signal with a radio frequency (RF: Radio Frequency) to transmit from the antenna. The radio apparatus is also called the optical feeder radio apparatus.